Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 80.8000030517578 | Thousand metric tons of contained nitrogen | NA |
| 2004 | 166 | Thousand metric tons of contained nitrogen | 105.45% |
| 2005 | 170 | Thousand metric tons of contained nitrogen | 2.41% |
| 2006 | 170 | Thousand metric tons of contained nitrogen | 0.00% |
| 2007 | 170 | Thousand metric tons of contained nitrogen | 0.00% |
| 2008 | 78.9120025634766 | Thousand metric tons of contained nitrogen | -53.58% |
| 2009 | 50 | Thousand metric tons of contained nitrogen | -36.64% |
| 2010 | 50 | Thousand metric tons of contained nitrogen | 0.00% |
